Package it.unimi.dsi.webgraph.labelling

Class ArcRelabelledImmutableGraph

java.lang.Object

it.unimi.dsi.webgraph.ImmutableGraph

it.unimi.dsi.webgraph.labelling.ArcLabelledImmutableGraph

it.unimi.dsi.webgraph.labelling.ArcRelabelledImmutableGraph

All Implemented Interfaces:

FlyweightPrototype<ImmutableGraph>

public class ArcRelabelledImmutableGraph
extends ArcLabelledImmutableGraph

Exhibits an arc-labelled immutable graph as another arc-labelled immutable graph changing only the kind of labels. Labels of the source graphs are mapped to labels of the exhibited graph via a suitable strategy provided at construction time.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	ArcRelabelledImmutableGraph.LabelConversionStrategy	A way to convert a label into another label.

Nested classes/interfaces inherited from class it.unimi.dsi.webgraph.ImmutableGraph

ImmutableGraph.LoadMethod

Field Summary

Fields

Modifier and Type	Field	Description
static ArcRelabelledImmutableGraph.LabelConversionStrategy	INT_LABEL_CONVERSION_STRATEGY	A conversion strategy that converts between any two classes extending AbstractIntLabel.

Fields inherited from class it.unimi.dsi.webgraph.labelling.ArcLabelledImmutableGraph

UNDERLYINGGRAPH_PROPERTY_KEY, UNDERLYINGGRAPH_SUFFIX

Fields inherited from class it.unimi.dsi.webgraph.ImmutableGraph

GRAPHCLASS_PROPERTY_KEY, NUMBER_OF_THREADS_PROPERTY, PROPERTIES_EXTENSION

Constructor Summary

Constructors

Constructor	Description
ArcRelabelledImmutableGraph(ArcLabelledImmutableGraph wrappedGraph, Label newLabelPrototype, ArcRelabelledImmutableGraph.LabelConversionStrategy conversionStrategy)	Creates a relabelled graph with given label prototype.

Method Summary

Modifier and Type	Method	Description
ArcRelabelledImmutableGraph	copy()	Returns a flyweight copy of this immutable graph.
boolean	hasCopiableIterators()	Whether the node iterators returned by this graph support NodeIterator.copy(int).
static void	main(java.lang.String[] arg)
ArcLabelledNodeIterator	nodeIterator(int from)	Returns a node iterator for scanning the graph sequentially, starting from the given node.
int	numNodes()	Returns the number of nodes of this graph.
int	outdegree(int x)	Returns the outdegree of a node.
Label	prototype()	Returns a prototype of the labels used by this graph.
boolean	randomAccess()	Checks whether this graph provides random access to successor lists.
ArcLabelledNodeIterator.LabelledArcIterator	successors(int x)	Returns a lazy iterator over the successors of a given node.

Methods inherited from class it.unimi.dsi.webgraph.labelling.ArcLabelledImmutableGraph

equals, labelArray, load, load, loadOffline, loadOffline, loadOnce, loadSequential, loadSequential, nodeIterator, toString

Methods inherited from class it.unimi.dsi.webgraph.ImmutableGraph

basename, hashCode, load, loadMapped, loadMapped, numArcs, outdegrees, splitNodeIterators, store, store, successorArray

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

INT_LABEL_CONVERSION_STRATEGY

public static final ArcRelabelledImmutableGraph.LabelConversionStrategy INT_LABEL_CONVERSION_STRATEGY

A conversion strategy that converts between any two classes extending AbstractIntLabel.

Constructor Details

ArcRelabelledImmutableGraph

public ArcRelabelledImmutableGraph(ArcLabelledImmutableGraph wrappedGraph, Label newLabelPrototype, ArcRelabelledImmutableGraph.LabelConversionStrategy conversionStrategy)

Creates a relabelled graph with given label prototype.

Parameters:

wrappedGraph - the graph we are going to relabel.

newLabelPrototype - the prototype for the new type of labels.

conversionStrategy - the strategy to convert the labels of the wrapped graph into the new labels.

Method Details

copy

public ArcRelabelledImmutableGraph copy()

Description copied from class: ImmutableGraph

Returns a flyweight copy of this immutable graph.

Specified by:

copy in interface FlyweightPrototype<ImmutableGraph>

Specified by:

copy in class ArcLabelledImmutableGraph

Returns:

a flyweight copy of this immutable graph.

See Also:

FlyweightPrototype

nodeIterator

public ArcLabelledNodeIterator nodeIterator(int from)

Description copied from class: ArcLabelledImmutableGraph

Returns a node iterator for scanning the graph sequentially, starting from the given node.

This implementation strengthens that provided in ImmutableGraph, but calls the labelled random-access method ArcLabelledImmutableGraph.successors(int).

Overrides:

nodeIterator in class ArcLabelledImmutableGraph

Parameters:

from - the node from which the iterator will iterate.

Returns:

an ArcLabelledNodeIterator for accessing nodes, successors and their labels sequentially.

See Also:

ImmutableGraph.nodeIterator()

successors

public ArcLabelledNodeIterator.LabelledArcIterator successors(int x)

Description copied from class: ImmutableGraph

Returns a lazy iterator over the successors of a given node. The iteration terminates when -1 is returned.

This implementation just wraps the array returned by ImmutableGraph.successorArray(int). Subclasses are encouraged to override this implementation.

The semantics of this method has been significantly modified in WebGraph 2.0 to take advantage of the new, faster lazy architecture.

Specified by:

successors in class ArcLabelledImmutableGraph

Parameters:

x - a node.

Returns:

a lazy iterator over the successors of the node.

prototype

public Label prototype()

Description copied from class: ArcLabelledImmutableGraph

Returns a prototype of the labels used by this graph. The prototype can be used to produce new copies, but must not be modified by the caller.

Specified by:

prototype in class ArcLabelledImmutableGraph

Returns:

a prototype for the labels of this graph.

numNodes

public int numNodes()

Description copied from class: ImmutableGraph

Returns the number of nodes of this graph.

Albeit this method is not optional, it is allowed that this method throws an UnsupportedOperationException if this graph has never been entirely traversed using a node iterator. This apparently bizarre behaviour is necessary to support implementations as ArcListASCIIGraph, which do not know the actual number of nodes until a traversal has been completed.

Specified by:

numNodes in class ImmutableGraph

Returns:

the number of nodes.

randomAccess

public boolean randomAccess()

Description copied from class: ImmutableGraph

Checks whether this graph provides random access to successor lists.

Specified by:

randomAccess in class ImmutableGraph

Returns:

true if this graph provides random access to successor lists.

hasCopiableIterators

public boolean hasCopiableIterators()

Description copied from class: ImmutableGraph

Whether the node iterators returned by this graph support NodeIterator.copy(int).

This implementation just returns ImmutableGraph.randomAccess().

Overrides:

hasCopiableIterators in class ImmutableGraph

Returns:

true if this graph provides copiable iterators.

outdegree

public int outdegree(int x)

Description copied from class: ImmutableGraph

Returns the outdegree of a node.

Specified by:

outdegree in class ImmutableGraph

Parameters:

x - a node.

Returns:

the outdegree of the given node.

main

public static void main(java.lang.String[] arg) throws JSAPException, java.io.IOException, java.lang.IllegalArgumentException, java.lang.SecurityException, java.lang.IllegalAccessException, java.lang.reflect.InvocationTargetException, java.lang.NoSuchMethodException, java.lang.ClassNotFoundException, java.lang.InstantiationException

Throws:

JSAPException

java.io.IOException

java.lang.IllegalArgumentException

java.lang.SecurityException

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

java.lang.NoSuchMethodException

java.lang.ClassNotFoundException

java.lang.InstantiationException